System and method of producing wafer

ABSTRACT

A system and method of manufacturing wafers are provided suitable for a semiconductor manufacturing system and a method thereof capable of shortening the processing period composed of a series of processes applied to objects to be processed, mainly carry out processes and conveyance peace by peace, and which can manufacture even various kings of products. The system is provided with a plurality of processing units each having therein a conveying mechanism, and is provided therein with a conveyer device for conveying the objects to be processed to the processing units. Further, the conveyer device includes loader conveying means which is laid along object transferring ports of the plurality of processing units across the object transferring ports of not less than two of the processing units, and a running robot which runs across not less than two of the object transferring ports, and a transferring robot for transferring the objects to be processed from the running robot to the processing units through the transferring ports, are arranged in the loader means. The loader means is shielded and provided with a purifying device so as to define an atmospheric pressure space conveying path.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a division of application Ser. No. 10/083,378filed on Feb. 27, 2002. The contents of application Ser. No. 10/083,378are hereby incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a wafer manufacturing system anda wafer manufacturing method, which can cope with a process module forprocessing an object to be processed (which will be hereinafter referredto “wafer”) such as a semiconductor substrate, a liquid crystalsubstrate or a component substrate.

[0004] 2. Related Art

[0005] Conventionally, as disclosed in, for example, “Operation Of LSIProduction System Which Can Reduce Investment For Development and CopeWith Variety Of Needs”, Nikkei Micro-Device, August, 1992 Pages 66-74,the conveyance of an object to be processed among a plurality ofprocessing units, have carried out such a manner that a plurality ofwafers, that is, the so-called lot, as a unit, are conveyed in a batch.As far as the wafers are processed in a batch, a processing timecorresponding to a number of wafers in a lot, is required in order toprocess the lot, and accordingly, the waiting time to the next processbecomes longer.

[0006] On the other hand, as disclosed in JP-A-4-130618 andJP-A-7-122622, there have been proposed a manufacturing system and amanufacturing method which utilizes one-piece conveying devices forconveying wafers one by one among a plurality of processing units inseries so as to shorten the complete process consisting of steps inseries in order to aim at enhancing the yield.

[0007] In the conventional system, with the use of a plurality ofprocessing units in series for processing, since no consideration hasbeen made for avoiding crossing wafers to be conveyed one another, andthe control and management of processing and conveying wafers one by onehas been complicated, and accordingly, it has been very difficult in anactual mass-production firm in which wafers are successively processed.Further, since the total system consisting of a plurality of modulesincluding various film forming units, a resist coating unit, variousetching units and various inspection units is connected to a singlering-like piece conveying device such as, for example, a conveyer,through the intermediary of interface sections, the system becomeslarge-sized while a heavy load is exerted to the piece conveying deviceduring mass production, resulting in considerable lowering ofthrough-put. Further, for each of the processing units, a pair oftransferring mechanisms for loading and unloading the wafers, a waferidentification device and a buffer are arranged in an interface unitbetween each of the various processing devices and the ring-like piececonveying device, and accordingly, the system becomes further complicateand large-sized.

[0008] Further, in another example, there has been proposed a loop-likepiece conveying device utilizing a belt which turns around in two tofour minutes while repeats a movement and a stop in a period of about 3seconds. It is described that the delivery of a wafer between aprocessing unit and the loop-like conveying device is completed in onesecond within the above-mentioned period of about three minutes.However, it is difficult to surely deliver a wafer at such a high speedas mentioned above. Further, although for each of the processing unit, awafer transferring robot should be provided in an inlet part thereof inorder to deliver the wafer between the processing units and theconveying device, it is not incorporated at present in a standardsystem. Thus, it is necessary to install a system which is designed witha special specification so as to be expensive and require a longdelivery time. Further, the loop conveying device requires a large floorarea so as to be contrary to the intension of cost reduction in theinvestment of plant and place including building. Further, since only aserial process is implemented, should one of units on a line fail, theentire line would come to a stop.

SUMMARY OF THE INVENTION

[0009] The present invention is made to solve the above-mentionedproblems, and accordingly, an object of the present invention is toprovide a manufacturing system and a manufacturing method which canshorten the time required for completing a series of process carried outfor an object to be processed, and which is flexible and inexpensive soas to be able to produce any of even various kind of articles in a shorttime, suitable for a system for and a method of manufacturing asemiconductor so as to mainly carry out a piece process and a piececonveyance.

[0010] The above object can be achieved according to the presentinvention, in the following processes. With respect to a concept of aprocessing apparatus for transferring an object to be processed betweena mini-environment type object (wafer or the like) storage containersuch as the one corresponding to a FOUP (Front Opening Unified Pod) orSMIF and the body of a processing unit which have been standardized for300 mm diameter semiconductor processing units, by way of a robotlocated in an atmospheric pressure clean space (refer to SEMI-E106-0301of SEMI Standards), there is provided such a configuration that acleaned atmospheric conveying zone provided in a shield space, for eachof a plurality of processing units within this concept is developed intoa common atmospheric pressure conveying zone which is common among theprocessing units so as to constitute each of a plurality of processmodules, and sample transferring places are laid among the plurality ofprocess modules, and between the process modules and the conveying andtransferring zone in order to process a sample by way of the pluralityof modules.

[0011] According to the above-mentioned configuration for solving theproblems, since the concept for piece process sequence is applied foreach of the plurality of process modules (which will be hereinafterabbreviated as “subsystem”), the process waiting time required for eachadjacent processing units and caused during a lot process can be greatlyreduced, and the total time from the introduction of a sample to thecompletion for the sample can be greatly shortened. Further, since eachof the processing units is built up with the processing units by arelatively small number, the load of the common atmospheric pressureconveying device part is greatly reduced, whereby it is possible toprevent the through-put of the process modules from being lowered evenon a mass-production base.

[0012] If a series of units for a multi-layer wiring process whichcarries out repetition of treatment or the like, is composed of thesesubsystems with the above-mentioned concept, the above-mentionedtechnical effects and advantages can become higher.

[0013] Since the conveyance between the above-mentioned subsystems orbetween the subsystem and a conventional device can be used incombination with conventional lot conveyance (AGV, RGV, OHS, OHT or thelike) with the use of a mini-environment type object storage containersuch a FOUP, the degree of freedom of the system can be greatly enhancedin comparison with the conventional configuration in which theconveyance is limited only to the piece conveyance.

[0014] Specifically, the present invention provides a system and amethod as explained below:

[0015] According to the present invention, there is provided a wafermanufacturing system incorporating a plurality of processing units eachhaving therein a conveyance mechanism and laid in a line, and aninter-unit conveyer devices for conveying an object to be processedbetween the processing devices, the inter-unit conveyer device having aloader conveying means laid along object transferring ports of theplurality of processing units which are arranged in a line, andextending across more than two of the object transferring ports, theloader conveying means being arranged herein with a running robot whichruns among more than two of the object transferring ports and atransferring robot for transferring the object to be processed on therunning robot onto one of the processing units, and further, theinter-unit conveyer device being shielded and provided with a purifyingdevice so as to define an atmospheric pressure space conveying path, andbeing arranged in the atmosphere.

[0016] According to the present invention, there is provided a a wafermanufacturing method comprising the steps of processing objects to beprocessed by means of a plurality of processing units each having atleast one processing chamber and a conveying mechanism, temporarilystoring the objects to be processed in order to introduce or deliver theobject to be processed, conveying an object to be processed to aposition around a desired one of the plurality of processing unitsthrough an atmospheric pressure clean space path in a loader conveyingmeans, transferring the object to be processed between the desiredprocessing unit and each of the loader conveying means with a timingwhich is different among the processing units, transferring the objectto and from the loader conveying means through the atmospheric pressurespace path therein, and conveying the same.

[0017] Other objects, features and advantages of the invention willbecome apparent from the following description of the embodiments of theinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0018]FIG. 1 is a view illustrating a configuration of an embodiment ofthe present invention;

[0019]FIG. 2 is a sectional view illustrating the configuration shown inFIG. 1;

[0020]FIG. 3 is a detailed view illustrating a part shown in FIG. 1;

[0021]FIG. 4 is a detailed view of a part shown in FIG. 3;

[0022]FIG. 5 is a view illustrating a configuration of anotherembodiment of the present invention;

[0023]FIG. 6 is an operation timing chart in FIG. 1;

[0024]FIG. 7 is another operation timing chart according to the presentinvention;

[0025]FIG. 8 is a further operation timing chart according to thepresent invention;

[0026]FIG. 9 is a view illustrating the configuration of anotherembodiment shown in FIG. 5;

[0027]FIG. 10 is a view illustrating an example of conveyance of awafer;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Embodiments of the present invention will be described withreference to the accompanying drawings.

[0029] FIGS. 1 to 4 show a first embodiment, and FIG. 1 shows aconfiguration of the first embodiment, FIGS. 2 and 3 show parts shown inFIG. 1, in detail, respectively, and FIG. 4 shows a part shown in FIG.3.

[0030] Referring to FIG. 1, a wafer manufacturing system 100 which copeswith a process module for processing a semiconductor substrate, a liquidcrystal substrate or a component part substrate (wafer) includes variouskinds of vacuum-processing units with which constitute, for example, alithographic process 1, an etching/cleaning process 2 and a film formingprocess 3. These processes can be optionally changed in dependence upona kind of component parts to be manufactured.

[0031] As shown in this figure, the plurality of processing units 11,12, 13, 14 are arranged in a line, and respectively consist of 11 a, 11b, 11 c, 11 d, 11 e, 11 g; 12 a, 12 b, 12 c, 12 d, 12 e; 13 a, 13 b, 13c, 13 d, 13 e, 13 f; and 14 a, 14 a, 14 b, 14 c, 14 d, 14 e.

[0032] The processing units 11 a to 11 g, 12 a to 12 e, 13 a to 13 f,and 14 a to 14 e are arranged in a line, respectively, each havingtherein a conveyance mechanism. A loader conveying means 22, 23 forconveying objects to be processed to the processing units are arrangedalong the processing units 11, 12, 13, 14. The processing units 11, 12and the processing units 13, 14 are arranged being opposed to eachother, respectively, and the loader conveying means 22, 23 are arrangedbetween processing unit 11 and the processing unit 12, and between theprocessing unit 13 and the processing unit 14, respectively. The loaderconveying means 22 corresponds to a first conveying means, and theloader conveying means 23 corresponds to a second conveying means.

[0033] Each of the processing units has a load lock chamber (includingan unload lock chamber) 21 (21 a, 21 b) facing the loader conveyingmeans 22, 23, and the load lock chambers of the processing units 11, 12,13, 14 are arranged on a straight line. Gate valves are arranged on theinlet side and the outlet side of each of the load lock chamber, thegate valve arranged on the inlet side serves as an object transferringport. It is noted that in a system which carries out a process under theatmospheric pressure, such as CMP (Chemical Mechanical Polishing), theload lock chamber 21 can be changed into a wafer transferring zone inthe ordinary pressure atmosphere.

[0034] An inter-unit conveyer device has the loader conveying means 22,23 which are extended across more than two processing units, andconveying and transferring means 42 for transferring an object to beprocessed to and from the plurality of loader conveying means andconveying the same, defining an atmospheric pressure space conveyingpath, and is shielded so as to be additionally provided with a purifyingdevice (means) while it is arranged in the atmosphere. With thisarrangement, the space required to be purified, can be less even thoughthe entire system is composed of a plurality of processing unitsarranged in a line, thereby it is possible to reduce the costs requiredfor purification. It is noted that the atmospheric pressure spaceconveying path shielded and additionally provided with the purifyingmeans is normally set at a pressure slightly higher than the atmosphericpressure, and accordingly, it is taken into consideration that the riskof entry of dust from an atmospheric zone becomes as low as possible.

[0035] Rails 24, 25 are laid in the loader conveying means 22, 23,respectively, which may be substituted by other means. For example,instead thereof, conveyers may be used. Running robots 26, 27 areprovided on the rails 24, 25, respectively, in order to run thereon.These running robot 26, 27 includes buffer cassettes 28, 29 carriedthereon for holding objects to be processed loaded on the running robots26, 27 and adapted to be transferred onto the processing units 13, 14,and transferring robots 30, 31 are provided to the processing units 13,14. Further, each of the processing units 11, 12, 13, 14 may includetherein an inspection device for inspecting foreign object or the like,and a measuring device for measuring a processing function. Thetransferring robots 30, 31 have arms which extend through thetransferring ports, respectively, and which are horizontally rotatable.Accordingly, the conveyer device (means) can be constituted. The armscarried by the transferring robots 30, 31 on their opposite sides willbe denoted as first arms 30 a, 31 a, and second arms 30 b, 31 b,respectively.

[0036] The loader conveying means 22, 23 hold objects to be processed,and is adapted to transfer the objects to be processed to and from FOUPdevices consisting of FOUPs arranged in the atmosphere. In the caseshown in the figure, the FOUP devices 32A, 32B consist of seven FOUPs32Aa, 32Ab, 32Ac, 32Ad, 32Ae, 32Af, 32Ag, and four FOUPs 32Bz, 32Bb,32Bc, 32Bd.

[0037] Each of the FOUPs defines therein an atmospheric pressure spacewhich is shielded. The atmospheric pressure space is opened by a gateopening means provided in each of the FOUPs when an object to beprocessed is transferred. As to the gate opening means, a well-knowmeans may be used. The objects to be processed are delivered one by onefrom the atmospheric pressure spaces in the FOUPs into the firstconveying path and the second conveying path through the transferringport constituted by the gate by means of the transferring robots 30, 31.It is noted that the FOUP device may be provided at least one positionin a single process module although FIG. 1 shows such a configurationthat the process module and the FOUP conveyer device 41 are connectedwith each other through the intermediary of the FOUP devices 32A, 32Blocated at two positions. In the configuration shown in FIG. 1, thesecond FOUP device 32A is provided in order to aim at improving thethrough-put in the case of using only a part of the process module, suchas a lithographic process step or the lithography process step and anetching/cleaning step.

[0038] The loader conveying means 22, 21 are laid, being straightline-like, and include buffer cassettes 35, 36, 37, 38 arranged onopposite sides thereof. Objects to be processed, which are conveyed onthe atmospheric pressure space conveying path are held in an atmosphericpressure condition by means of the buffer cassettes 35, 36; 37, 38.

[0039] Conveying and transferring means 42, 43 as other conveyer devicesare laid in a direction crossing the loader conveying means 22, 23 whichare laid in a plurality of parallel systems. The conveying andtransferring means 42 serves as a third conveying path and the conveyingand transferring means 43 serves as a fourth conveying path.

[0040] The FOUP conveyer devices 41, 44, 45 are provided therein withFOUP transferring devices 16, 47, 48 and the like, the FOUPs arecontinuously conveyed as indicated by the arrows by way of branchingpoints, and accordingly, the FOUPs can be transferred to and from FOUPpedestals 32Aa to 32Ag, 32Ba to 32Bf.

[0041] Running robots 51, 52 are provided on the third and fourthconveying paths, respectively, and are mounted thereon with buffercassettes 55, 56, respectively.

[0042] Inter-path buffer cassettes 35, 36, 37, 38 serve as objectholding storages between the conveying paths so as to manage thetransferring of the objects to be processed which are conveyed on thefirst, second, third and fourth conveying path onto other conveyingpaths,

[0043]FIG. 2 is an enlarged sectional view which shows the system shownin FIG. 1, in order to explain a method of conveying objects to beprocessed into a vacuum processing unit as a processing unit.

[0044] The manufacturing system includes a vacuum processing device zoneA and a loader conveying means zone B.

[0045] In the vacuum processing unit zone A, there are horizontallyarranged a load lock chamber (A1) 21, a vacuum conveying chamber (A2) 62and a processing chamber (A3) 63. As shown in the figure, gate valves64, 65, 66 are provided in an inlet part of the load lock chamber 21,and an inlet part and an outlet part of the vacuum conveying chamber 62,respectively. A conveying robot 67 incorporating arm is provided in thevacuum conveying chamber 62 while a processing bed is provided in eachof the processing chambers (which have a plural number in many cases),and an object loading bed 69 is provided in the load lock chamber 21.

[0046] It is noted that the load lock chamber may be changed into awafer transferring means in a device which carries out a process underthe atmospheric pressure, as mentioned above, and accordingly, it goeswithout saying that all or a part of the gate valves 64, 65, 66 may beeliminated.

[0047] The two zones are incorporated in one integral unit through theintermediary of the gate valve 64. A filter 82 for feeding purified airis added to the conveying path in the loader conveying means 22 in orderto introduce purified air.

[0048] The running robot 26 is set on the rail 24, and the transferringrobot 30 is provided on the running robot 26 so as to be verticallymovable. The transferring robot 30 has a first arm 30 a and a second arm30 b which are adapted to extend through the transferring ports of theFOUPs 32Aa to 32Ag so as to receive or deliver objects to be processedthrough the transferring ports of the FOUPs 32Aa to 32Ag. Further, an IDsensor 89 and a sample center/direction adjusting unit 88 are mounted onthe buffer cassette 28 on the running robot and in a samplecenter/direction adjusting space 85. As mentioned above, the loaderconveying means 22 includes the FOUPs 32Aa to 32Ag, and the atmosphericpressure space in the loader conveying means 22 is communicated with theatmospheric pressure spaces of the FOUPs 32Aa to 32Ag when a gateincorporated in the loader conveying means is opened so that the outersurfaces thereof are exposed to the atmospheric air, and accordingly,the spaces in the loader conveying means 22, 23 are decreased.

[0049] The FOUPs 32Aa to 32Ag are set on a FOUP cradle 83. FIG. 3 is aview for explaining such a situation that an object to be processed istransferred between the inter-path buffer cassette 36 and the conveyingpath.

[0050] As mentioned above, the running robot 26 runs on the rail 24, andthe transferring robot 30 is mounted on the running robot 26. Further,the transferring robot 26 has the first arm 32 a and the second arm 32b. The buffer cassette 28 is carried on the running robot 26. The buffercassette 28 has a plurality of racks for holing a plurality of objects86 to be processed.

[0051] The ID sensor 28 and the sample center/direction adjusting unit88 are provided in the lower part of the buffer cassette 28.

[0052] The buffer cassette 28 on the running robot is opposed to theinter-path buffer cassette 36 at the terminal end part of the loadconveying means 22.

[0053] The inter-path buffer cassette 36 is mounted on the cradle 90 andsupports a plurality of racks 92, and holds therein a plurality of racks92, and the objects to be processed is transferred between the buffercassette 28 on the running robot 26 and the inter-path buffer cassette36.

[0054] The objects to be processed are transferred into the buffercassette 54 mounted on the conveying robot 52 which runs on a rail 93laid in the fourth conveying path, from the inter-path buffer cassette36 by means of the arm 56.

[0055]FIG. 4 is a view for explaining such a situation that the arm 30a, the ID sensor 89 and the sample center/direction adjusting unit 33are arranged. With these equipments, a number of an object to beprocessed is identified by the ID sensor 89, and the sample center andthe direction are adjusted by the sample center/direction adjusting unit88. The arm 30 b can carry out motion similar to that of the arm 32 a.

[0056] As mentioned above, the loader conveying means 22, 23 include therunning robots 26, 27 which are mounted thereon with the transferringrobots 30, 31 for transferring objects to be processed to and from theprocessing units 11 to 14, and the robot running space is provided withthe purifying means and is shielded from the other parts so as to definea shield space.

[0057] Thus, there can be provided a manufacturing system in which aplurality of processing units are connected by means of the inter-pathbuffer cassette which can be accessed from its opposite sides.

[0058] The buffer cassette 28 on the running robot serving as an objectstorage means which can accommodate therein a plurality of object to beprocessed, for introducing and delivering an object to be processed intoand from a processing unit is provided in the shield space.

[0059] The load lock chamber 21 which serves as a transferring space toand from at least one vacuum processing unit exhibits a vacuum conditionand an atmospheric pressure condition, and the transferring of theobject to be processed to and from the conveyer device is carried outwhen the load lock chamber 21 exhibits the atmospheric pressurecondition. The load lock chamber 21 defines therein one or two chambers.In the case of the two chambers, there may be used one of them as a loadlock chamber, and the other one of them as an unload lock chamber, orthere also may be used both of them independent from each other asbidirectional load lock chambers. Further, as mentioned above, in asystem in which a process is carried out under the atmospheric pressure,such as CMP, the load lock chamber 21 can be changed into a transferringzone for objects to be processed in an atmospheric pressure condition.

[0060] The objects to be processed are transferred basically one by onebetween the load conveying means or the conveyer device in the conveyingand transferring means and the processing units.

[0061] Further, a measuring device for measuring characteristics (forexample, foreign object, a film thickness a processed shape or the like)of an object to be processed before ant after processing, may bearranged adjacent to the load conveying means or the conveying andtransferring zone so as to enable the object to be processed to betransferred thereto.

[0062] By installing and running the sample transferring robot having anarm mechanism and a lifting mechanism in the cleaned common atmosphericpressure conveying zone, a sample can be transferred to and from theprocessing unit side with the provision of a sample cradle alone or asample cradle with a mechanism such as a lifting mechanism or a pinlifting mechanism. In particular, in a 300 mm diameter semiconductorprocessing unit, the transferring of a sample to the processing unitbody from the atmospheric pressure conveying means exhibits high merits.No conventional several arms and a transferring mechanism provided foreach of the processing units are required between the conveyer deviceand the processing units, and accordingly, the configuration of thesystem can be simplified, thereby it is possible to expect enhancing thereliability and greatly lowering the system cost.

[0063] It is noted that with the addition of the ID sensor 89 or asample ID reader, the sample center/direction adjusting unit 88 and thelike in the zone where the sample transferring robot is installed, thereare exhibited such advantages that the confirmation and the correctioncan be made so as to facilitate the management of samples, and theinitialization of samples, and further, that the number of ID sensors 89or ID readers and the number of the sample center/direction adjustingunits, each having conventionally been provided for each of theprocessing unit, can be greatly reduced.

[0064] It is noted that the conveying and transferring means 43 and theinter-path buffer cassettes 36, 38 may be eliminated in order tosimplify the system configuration while the loader conveying means 22,23 are crossed over the conveying and transferring means 42 at their oneend although the time required for the conveyance becomes longer.Further, one of the FOUP devices 32A, 32B may be eliminated or thenumber thereof reduced, or they may be laid adjacent to the conveyingand transferring means 42.

[0065]FIGS. 6, 7 and 8 are timing charts which show the stream of waferswhen a FOUP accommodating therein wafers is introduced into the FOUPdevice 32B on the second conveying path, with the time being taken alongthe abscissa (No FOUP device 32A is used in this case).

[0066]FIGS. 6 and 7 show such a configuration that one film formingdevice in which a heating chamber, a plurality of film forming chambersand conveyer mechanism therebetween are synthesized, is installed on thesecond conveying path, and one lithography device, one etching deviceand one cleaning device are installed on the first conveying path. FIG.6 shows a configuration in the case of such a process that wiring ismade in one layer, and FIG. 7 shows a configuration in such a case thatwiring is made in multiple layers. There is shown such a case that eachof the units also includes a plurality of processing chambers, and apre-processing chamber and a post-processing chamber for this process,and receiving a wafer onto each unit and extracting a wafer from eachunit can be made within 6 minutes while receiving and extracting a waferat each unit can be made in a three minute cycle period (T in thefigures shows 3 minutes).

[0067] Numerals in the figures are numbers of wafers, and numeralssurrounded by a circle exhibit delivery of wafers from the units(including the inter-path buffer cassette and the FOUP) onto theconveyer device, and the numerals with no circle show timings ofreceiving wafers from the conveyer device onto the units.

[0068] When six layers are processed with the timings shown in FIG. 7,the time Ts from the start of processing for a first wafer to thecompletion of processing for an N-th wafer is given by the followingformulae (Incidentally, FIG. 7 shows timings in the case of N=10, but inthe case of N≧11, a wafer which has been returned to the inter-pathbuffer cassette 38 on the original second conveying path is temporarilyaccommodated in the FOUP 32B, and is then conveyed again aftercompletion of a wafer on the previous stage).

N=1: Ts=3 min.×10 Time Slots×6 Layers=180 min

N=5: Ts=3 min.×10 Time Slots×6 Layers+3 min.×4=192 min

N=10: Ts=3 min.×10 Time Slots×6 Layer+3 min.×9=180 min.

N≧11: Ts=3 min.×10 Time Slots×6 Layer+3 min.×9=180 min.

N=24: Ts=459 min.

[0069] Meanwhile, in the case of a conventional configuration in whichwafers are conveyed between units in a FOUP as a unit, if 6 layers areprocessed, the time Tb required from a start of processing of a firstwafer to a completion of processing of N-th wafer is exhibited by thefollowing formula:

Tb=((6 min.+(N−1)×3 min.)+t)×4 devices×6 layers

[0070] where t is a time (minutes) required for conveying a FOUP betweenthe units, which is estimated as 2 minutes in the following case:

N=1: Tb=192 min.

N=5: Tb=480 min.

N=10: Tb=840 min.

N=24: Tb=1848 min.

[0071] In the case of processing a single wafer, that is, N=1,substantially no difference is appreciated between Ts in theconfiguration according to the present invention and Tb in theconventional configuration, which exhibit a total processing time, butin the case of N=5, Ts becomed less than a half of Tb while in the caseof N≧10, and Ts becomes less than a quarter of Tb so that it is greatlyshortened.

[0072] This improvement can be enhanced as the number of layers to beprocessed and the number of units used per layer are increased.

[0073] In comparison with a conventional piece conveying path system inwhich wafers are transferred one by one onto processing units by meansof a single conveying path, in the system according to the presentinvention, in which a plurality of conveying paths are coupled with oneanother by means of the inter-path buffer cassettes, although the totalprocessing time must be increased more or less by the time required forcarrying our several conveyances, the time which can be used fortransferring between the loader conveying means and the processing unitscan be increased, and accordingly, there can be offered such anadvantage that the reliability can be enhanced while stable operationcan be obtained. Further, no complete synchronization is required amonga plurality of the loader conveying means, and accordingly, the freedomof operation of the loader conveying means can be increased, thereby itis possible greatly facilitate the scheduling of the operation.

[0074]FIG. 8 shows such a configuration that two film forming devicesare installed on the second conveying path while two lithographydevices, two etching devices and one washing device are installed on thefirst conveying path. In this case, a plurality of layers aresuccessively processed, and the processing for each odd number of alayer is carried out by devices for film formation 1, lithography 1,etching 1 and cleaning 1 while the processing for each even number of alayer is carried out by devices for film formation 2, lithography 2 andetching 2. It is noted that a washing function for each odd number layeris incorporated in the device for etching 2. Similar to FIGS. 6 and 7,FIG. 8 shows such a case that receiving a wafer onto each unit anddelivering a wafer from each unit can be made within 6 minutes whilereceiving and delivering a wafer at each unit can be made in a threeminute cycle period (T in the figures shows 3 minutes).

[0075] In zones of the inter-path buffer cassettes 35, 36, 37, 38, partswhere numerals are juxtaposed thereto, are those in which a plurality ofwafers are accommodated in the buffer cassette. Although there is causeda waiting time between the processing of an odd number layer and theprocessing of an even number if N is greater than 11 in the case of FIG.7, if different devices are used respectively for an odd number waferand an even number wafer, as shown in FIG. 8, no waiting time asmentioned above is caused, thereby it is possible to greatly shorten thetotal processing time in the case of a large number of wafers.

[0076] By uccessively increasing the number of devices installed in theloader conveying means in accordance with a number of wafers introducedas mentioned above, the total processing time can be flexibly shortened.

[0077] Further, if the number of process module lines each composed of aplurality of loader conveying means is increased, it can cope with alarger number of wafers.

[0078] The manufacturing method in this embodiment comprises the stepsof processing an object to be processed with at least two processingunits each having at least one processing chamber and a conveyingmechanism, transferring the object to be processed between differentprocessing units through the intermediary of a loader conveying means,temporarily holding objects to be processed in a storage means in orderto introduce and deliver the objects to and from a manufacturing system,transferring the object to be processed to and from the loader conveyingmeans in object transferring spaces in a desired processing unit and thestorage means, conveying the object to be processed to a desiredposition by means of the loader conveying means, and transferring theobjects to and from the loader conveying means, and conveying the same,wherein the object to be processed is transferred between a desiredprocessing unit and the loader conveying means with a timing which isdifferent among the processing units.

[0079] Further, the other manufacturing method comprises the steps ofprocessing an object to be processed with at least two processing unitseach having at least one processing chamber and a conveying mechanism,temporarily holding objects to be processed in a storage device in orderto introduce and deliver the objects to be processed into and from amanufacturing system, measuring a processed condition of an object to beprocessed with at least one measuring device, transferring the objectsto be processed between the processing unit and the measuring devicesthrough the intermediary of a loader conveying means, transferring theobject to be processed to and from the loader conveying means in objecttransferring spaces in a desired processing unit, the storage device andthe measuring device, conveying the object to be processed to a desiredposition by means of the loader conveying means, and conveying the sameto a desired position by means of the loader conveying means, whereinthe object to be processed is transferred among a desired processingunit, the storage means and the measuring means and the loader conveyingmeans with a timing which is different among the processing units, thestorage means and the measuring means.

[0080] In these manufacturing methods, there may be provided the step oftemporarily storing the object to be processed in the loader conveyingmeans between the steps of receiving the object to be processed onto theloader conveying means and delivering the object to be processed bymeans of the loader conveying means.

[0081] In the case of a simple system in which the loader conveyingmeans, the FOUP for transferring, the processing unit and the measuringdeice are arranged along a process sequence as shown in FIG. 6 or 7, thetransferring of an object to be processed as viewed from the runningrobot 26, 27 side, is carried out with the repetition of (A receiving),(A delivering), (B receiving) and (B delivering) in the mentioned order,and it is only sufficient to hold an object to be process in one of thetransferring robots 30, 31 on the running robots. Accordingly, thebuffer cassettes 28, 29 and the like on the running robots are notalways necessary. However, in the case of an actual process module, itis very rare that all devices are arranged along a process sequence. Inthis case, it should be better to carry out not less than two cycles ofreceiving, successively, such as (A receiving), (B receiving), (Adelivering), (C receiving) and (C delivering) and (B delivering) in thementioned order in transferring as viewed from the running robot side,in order to greatly simplify the running sequence of the running robotswhich shortening the time required for conveyance, thereby it ispossible to enhance the through-put of the process module. In order tocope with this case, according to the present invention, the buffercassettes 28, 29 are mounted on the running robots 26, 27, or aplurality of transferring robots are provided on the one of the runningrobots 26, 27, and accordingly, not less than two of objects to beprocessed can be simultaneously set on the running robot. Incidentally,a time slot shown in FIG. 8: in the case of 1-17 in which metal multilayer wiring is carried out in one and the same process module, thetransferring of the object to be processed as viewed from the runningrobot side, consists of (7-receiving), (17-receiving), (17-delivering),(15-receiving), (7-delivering), (5-receiving), (15-delivering),(13-receiving), (5-delivering), (3-receiving), (13-delivering),(11-receiving), (3-delivering) and (11-delivering) in the mentionedorder. In this case, although the timing with which two objects to beprocessed are simultaneously mounted on the running robot is caused atseveral positions, the running of the running robots can be greatlysimplified by installing the buffer cassettes 28, 29 on the runningrobots 26, 25 in order to add such a function that the objects to beprocessed are temporarily stored.

[0082] If a number of used devises are increased in the loader conveyingmeans in these manufacturing methods, the step of receiving an object tobe processed onto the transferring robot in the running robot, iscarried out for all necessary processing units, the storage device andthe measuring device in the loader conveying means so as to accommodatethem in the buffer cassettes 28, 29 on the running robots, and then,successively, the step of delivering and feeding the objects to beprocessed from the buffer cassettes 28, 29 on the running robots, bymeans of the transferring robots in the running robots, is carried outfor all necessary processing units, the storage device and the measuringdevice in the loader conveying means while the step of receiving theobject to be processed by the transferring robots in the running robotsis started at every predetermined cycle period. Thereby it is possibleto greatly simplify the method of running the running robots, theprocess sequence and the manufacturing method, and to enhance thethrough-put of the process.

[0083]FIG. 5 shows the configuration of another embodiment which isbasically similar to the embodiment shown in FIG. 1, and accordingly,like reference numerals are used to denote like parts. Further, theexplanation will be made of parts which are different from theembodiment shown in FIG. 1. Accordingly, those other than the partsshould be referred to the explanation as to FIG. 1.

[0084] While the embodiment shown in FIG. 1 is consists of thelithography process (11 a-11 c, 12 a), the etching/washing process (11d-11 g, 12 b-12 e) and the film forming process (13 a-13 f), (14 a-14e), the embodiment shown in FIG. 5 consists of a lithography process 1(L1, L2, L3), a metal film/insulation film-etching/washing/film-formingprocess 102 (Etching E1, E2, washing W1, W2, and filming forming D1,D2), a copper film forming process 103 (Dc1, Dc2, Dc3),copper/insulation film-CMP/washing process 104 (copper/insulationfilm-CMP Ec1, Ec2, Ec3) and Low-k film forming process 105 (D_(L) 1,D_(L) 2). The lithography process composed of a pretreatment such aswashing or the like, resist application, exposure, baking and the likegreatly affects the through-put of the entire system in the processmodule. Accordingly, a sole robot 128 is provided for the lithographyprocess in order to shorten the time required for the conveying pathduring the lithography process in the case show in FIG. 5.

[0085] For the processing units 11 a, 11 c, 11 d, 12 c, 13 a, 13 c, 13e, 13 g, 14 a and 14 e, there are ensured in installation spaces forexpansion.

[0086] Referring to the figure, there are shown L1(11 b), L2(12 a),E1(11 e), E2(12 d), W1(11 f), W2(12 e), D1(11 d), D2(12 f), Dc1(13 g),Dc2(13 f), Dc3(14 f), D_(L) 1(13 b), D_(L) 2(14 b), Ec1(13 d), Ec2(14 d)and Ec3(14 c).

[0087] Referring to the figure, a rail 24 is composed of two rails 24 a,24 b, and a running robot 126 is set on the rail 24 a, and thetransferring robot 128 is provided on the running robot 126 while thetransferring robot 128 has an arm 130 a and an arm 130 b. The runningrobot 26 is set on the rail 24 b, similar to that shown in FIG. 1.

[0088] A buffer cassette 106 is provided between the two rails, and thebuffer cassette 106 has a configuration similar to the buffer cassette84 shown in FIG. 3 so as to constitute an inter-path buffer cassettebetween the two rails.

[0089] Further, with the embodiment shown in FIG. 1 or FIG. 5, theatmospheric pressure peace conveying means which is cleaned, for each ofthe units provided in the shield space in this concept is broadened intoa common atmospheric pressure peace conveying means having aconfiguration which is common among a plurality of processing units soas to build up a single process module, and sample transferring placesare provided among a plurality of process modules or between the processmodules and the piece conveying mechanism in order to process samples byway of the plurality of modules, thereby it is possible to greatlyshorten the compete process consisting of steps in series applied forthe object to be processed.

[0090] It is noted that although the explanation will be made of such aconfiguration that the buffer cassettes are provided between a pluralityof loader conveying means arranged in each process module, the presentinvention should not be limited to this configuration but it can, ofcourse, also applied to a case in which the process module consists of asingle loader conveying means. For example, the present invention canalso applied to such a configuration that the units connected to theloader conveying means 23 are concentrated toward the loader conveyingmeans 22, and the conveying and transferring means 42, 43, the loaderconveying means 23, the buffer cassettes 35, 36, 37, 38 and the like areeliminated.

[0091] Further, explanation has been made of such a case that only onerunning robot 26, 27 is used in the loader conveying means withreference to FIGS. 1, 2, 3 and 5, the present invention should not belimited to this case, but a plurality of conveying lines or a loop-likeconveying line may be provided in a single loader conveying means.Although this configuration causes a disadvantage since themanufacturing costs for the manufacturing line are increased, there maybe presented such an advantage that a plurality of running robots can beprovided in a single loader conveying means, and accordingly, it ispossible to aim at either shortening the conveying time or enhancing themanufacturing through-put. Further, even though one of the runningrobots fails, the other one of the robots can be used in order tooperate the process module, thereby it is possible to enhance thereliability of the manufacturing line.

[0092]FIG. 9 shows another example, which is a variant form of theembodiment shown in FIG. 5. Although the loader conveying means 22, 23are configured linearly in the embodiment shown in FIG. 5, in thisexample, the running robots 26, 27 (which are the same as shown in FIG.4) are provided in the loop-like loader conveying means 22A, 23A,respectively. However, in this example, due to the loop-likeconfiguration, there may be provided a plurality of robots per loop,such as two robots in one of the loop-like loader conveying means inthis example, as show in the figure. It is noted that the thirdconveying path 24 which is one of the conveying and transferring meansin the direction crossing the loader conveying means 22, 23 iseliminated in the example shown in FIG. 9, and the fourth conveying path43 is used, substituted therefor.

[0093] As to the loop-like conveyance system, there are a contact typerail system and a non-contact type rail system. Further, as to thenon-contact type rail system, a linear type (using magnetism), a gaspressure type or a line detection type (using a conveyer belt) may beused. With the selection of the non-contact type rail system which canreduce slide parts thereof, it is possible to avoid friction.Accordingly, generation of particles such as abrasive powder caused bythe friction can be restrained so as to ensure a clean environment.Further, it is possible to prevent the yield of wafers from lowering,thereby the system can enhance the through-put.

[0094] The other components of this example are the same as those in theembodiment shown in FIG. 5, and accordingly, like reference numerals areused to denote like parts shown in FIG. 5 so as to avoid repeating thesame explanation.

[0095]FIG. 10 shows the motions for transferring the wafers between therunning robots and the devices in such a configuration that not lessthan two of running robots are used on a plurality of loop-likeconveying paths as the loader conveying means, the motions are sorted ingroups, type by type. Table 1 shows a configuration, a motion and anadvantage per type.

[0096] The present invention can be applied to running robots whichexhibits motions as given by Type A to Type E. TABLE 1 Type A RunningRobot: A running robot is provided for each of rows of processing units,and the respective robots comprise arms for transferring wafers one byone to and from the lock chamber for each processing units. TransferringWafer: (1) Running robot moves and stops at a position    correspondingto the lock chamber of each unit: (2) The arm delivers a wafer into thelock chamber    (introduction) or receives a wafer from the lock   chamber (delivery) in the condition (1); (3) The arm or the runningrobot which has been    delivered or received the wafer moves to another   position or place corresponding to a FOUP or a    lock chamber ofanother processing unit; (4) The control of operation of the respectiverunning    robots and the arms is independent from one    another.Advantage: The introduction and delivery of wafers into rows of the(Comparison With Single processing units laid opposite sides can besmoothly Path/Single running since the degree of freedom of motion ofthe running Robot) robot is high. As a result, the conveyance of thewafers can be efficiently made so as to enhance the procutivity. Type BRunning Robot The same as that of type A Difference from Type A: Tworunning robots are moved in a line and in synchronization with eachother. Transferring Wafer (1) Two running robots moves and stops atpositions    corresponding to lock chambers (two chambers    arearranged) of required processing units; (2) In the condition (1), forexample, the respective    arms receives wafer from the associated lock   chambers (introduction), and the left side arm    moves in thedirection indicated by the arrow in    order to receive a wafer fromanother rock    chamber; and (3) The respective robots are controlled inrelation to    each other. Type C Running Robot: The same as that oftype A. Difference from Type A: The respective arms can transfer wafersto and from lock chambers of processing units in rows which are laidopposite sides of the running path. Transferring Wafer (1) Therespective running robots move and stop at    positions which correspondto lock chambers of    respective necessary processing units: and (2) Inthe condition (1), the arms of the respective    running robots transferwafers to and from the    lock chambers of the respective necessary   processing units which are laid on opposite    sides. Type D RunningRoot: The same as that of type A. Difference from Type A The respectivearms can transfer to and from lock chambers (two chambers) of theprocessing units. Transferring Wafer (1) Running robots move and stop atpositions    corresponding to lock chambers (two chambers)    ofnecessary processing units; and (2) In the condition (1), the respectivearms transfer    wafers to and from the lock chambers (two    chambers)of necessary processing units. Type E Combination of Type A and Type B

[0097] As mentioned above, according to the present invention, theconcept of the peace processing sequence is applied among the processingunits through the process modules, and accordingly, the process waitingtime caused among the processing units during processing a lot ofobjects to be processed can be greatly reduced, thereby it is possibleto greatly shortened the time from the introduction of a sample to thecompletion of the sample. Further, since each of the process modules isbuilt up with a relatively small number of the processing units, theload upon the common atmospheric pressure peace conveying system can begreatly reduced, thereby it is possible to provide the system and themethod which can restrain the through-put of each process module fromlowering even on a mass production base. Further, since the conveyanceis carried out between the process modules with the use of themini-environment type object storage container such as a FOUP, thefreedom of conveyance between the modules can be increased in comparisonwith such a system in which all lines are unified by through peaceconveyance, thereby it is possible to rapidly and flexibly cope withvarious manufacturing processes.

[0098] It should be further understood by those skilled in the art thatthe foregoing description has been made on embodiments of the inventionand that various changes and modifications may be made in the inventionwithout departing from the spirit of the invention and the scope of theappended claims.

What is claimed is: 1: A wafer manufacturing method for use in a wafermanufacturing apparatus comprising a plurality of processing units eachhaving therein at least one processing chamber, a conveying mechanism,and a conveyer device for conveying objects to be processed to theprocessing units in an atmospheric pressure space which is arranged inan atmospheric air, and provided therein a purifying device, comprisingthe steps of: temporarily holding objects to be processed in a containerto introduce or deliver individual object to be processed; transferringthe objects to be processed between the container and the conveyerdevice; conveying an object to be processed to a position around adesired one of the plurality of processing units through an atmosphericpressure space conveying path in the conveyer device, transferring theobject to be processed between the desired processing unit and theconveyer device with a designated timing; processing the objects to beprocessed, via the plurality of processing units; and transferring theobjects to be processed between the processing units through theatmospheric pressure conveying path. 2: A wafer manufacturing method asclaimed in claim 1, further comprising a step of transferring objects tobe processed piece-by-piece between the desired processing unit, astorage device or a measuring device and the conveying mechanism with atiming which is different among the processing units, the storage deviceand the measuring device. 3: A wafer manufacturing method as claimed inclaim 1, further comprising a step of temporarily accommodating theobjects to be processed in the conveyer device between the steps ofreceiving the objects to be processed from the processing units to theconveyer device and the step of delivering the objects to be processedfrom the conveyer device to the processing units. 4: A wafermanufacturing method as claimed in claim 2, further comprising a step oftemporarily accommodating the objects to be processed in the conveyerdevice between the steps of receiving the objects to be processed fromthe processing units to the conveyer device and the step of deliveringthe objects to be processed from the conveyer device to the processingunits.